(In above two expressions Java would internally convert 5 in to “5” first and then concatenate with “xyz” and “” respectively.)

Increment/Decrement Operators (++, --)

Java includes two useful operators not generally found in other computer languages (expect C and C++). These are the increment and decrement operators, ++ and --. The operators ++ adds 1 to its operand, and – subtracts one.
In other words,a = a + 1;
is the same as++a ; or a++;
Anda = a – 1
is the same as--a ; or a --;

However, both the increment and decrements come in to two varieties: they may either precede of=r fallow the operand. The prefix version comes before the operand (as in ++ a or -- a) and the post-fix version comes after the operand (as in a++ or a--). The two version have the same effect upon the operand, but they differ when they take place in an expression.